func testSignCompact(t *testing.T, tag string, curve *btcec.KoblitzCurve,
data []byte, isCompressed bool) {
tmp, _ := btcec.NewPrivateKey(curve)
priv := (*btcec.PrivateKey)(tmp)
hashed := []byte("testing")
sig, err := btcec.SignCompact(curve, priv, hashed, isCompressed)
if err != nil {
t.Errorf("%s: error signing: %s", tag, err)
return
}
pk, wasCompressed, err := btcec.RecoverCompact(curve, sig, hashed)
if err != nil {
t.Errorf("%s: error recovering: %s", tag, err)
return
}
if pk.X.Cmp(priv.X) != 0 || pk.Y.Cmp(priv.Y) != 0 {
t.Errorf("%s: recovered pubkey doesn't match original "+
"(%v,%v) vs (%v,%v) ", tag, pk.X, pk.Y, priv.X, priv.Y)
return
}
if wasCompressed != isCompressed {
t.Errorf("%s: recovered pubkey doesn't match compressed state "+
"(%v vs %v)", tag, isCompressed, wasCompressed)
return
}
// If we change the compressed bit we should get the same key back,
// but the compressed flag should be reversed.
if isCompressed {
sig[0] -= 4
} else {
sig[0] += 4
}
pk, wasCompressed, err = btcec.RecoverCompact(curve, sig, hashed)
if err != nil {
t.Errorf("%s: error recovering (2): %s", tag, err)
return
}
if pk.X.Cmp(priv.X) != 0 || pk.Y.Cmp(priv.Y) != 0 {
t.Errorf("%s: recovered pubkey (2) doesn't match original "+
"(%v,%v) vs (%v,%v) ", tag, pk.X, pk.Y, priv.X, priv.Y)
return
}
if wasCompressed == isCompressed {
t.Errorf("%s: recovered pubkey doesn't match reversed "+
"compressed state (%v vs %v)", tag, isCompressed,
wasCompressed)
return
}
}
//SignMessage sign using bitcoin sign struct
func (key *Key) SignMessage(hash []byte) ([]byte, error) {
msg := make([]byte, 0)
msg = append(msg, []byte("\x18Bitcoin Signed Message:\n")...)
msg = append(msg, []byte{byte(len(hash))}...)
msg = append(msg, hash...)
h := sha256.Sum256(msg)
hh := sha256.Sum256(h[:])
s256 := btcec.S256()
sig, err := btcec.SignCompact(s256, key.Priv.key, hh[:], key.Pub.isCompressed)
if err != nil {
return nil, err
}
return sig, nil
}